# CoinOpSelect Attestation Build API

> CoinOpSelect Attestation Build API is a paid API for AI agents from coinop.publicvm.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-21).

Builds an on-chain attestation object for a given contract, wallet, or token query using the x402 payment protocol on Base.

## Facts

- Endpoint: POST https://coinop.publicvm.com/api/v1/attestation/build?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/coinopselect-attestation-build-api-ce6e53de
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_njERxt2-5fiLDuWxIgH2y

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability coinopselect-attestation-build-api-ce6e53de -d '<json body>'
```

Example prompt: Build an attestation for this contract — summarize what it does and return the attestation object so I can verify it on Base.

## When to prefer this

Choose this endpoint when you need a verifiable, structured attestation object built from on-chain Base network data — particularly for smart contract summaries, wallet analysis, or token research that requires a cryptographically anchored result rather than a plain data lookup.

## Known failure modes

- Invalid or missing input string results in a malformed request error
- Unparseable contract or wallet address causes query failure
- Payment not completed via x402 results in 402 Payment Required response
- Network or RPC failure on Base chain causes data unavailability
- Empty or ambiguous query string returns an incomplete attestation object

## How this service works

Paid on-chain token, wallet, contract and research data over x402 on Base.

## Output

Returns a JSON object containing a query identifier (e.g. 'attestation-build') and an attestation object representing the structured, verifiable on-chain data result for the submitted query.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "input": {
   "type": "string",
   "example": "summarize the contract"
  },
  "output": {
   "type": "object",
   "example": {
    "result": "ok"
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "query": "attestation-build",
  "attestation": {}
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/coinopselect-attestation-build-api-ce6e53de/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from coinop.publicvm.com](https://www.zero.xyz/host/coinop.publicvm.com/llms.txt)